Abstract:

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Char derived from pyrolysis of physic nut waste at 400-800°C was used for the
preparation of activated carbon by chemical impregnation of phosphoric acid and potassium
hydroxide. The original char exhibited the BET surface area in the range of 120-250 m2·g-1. The
surface area increased to 480 and 532 m2·g-1 when activated with H3PO4 and KOH, respectively.
Equilibrium adsorption data was found to be best represented by the Langmuir isotherm with
maximum monolayer adsorption capacity of 560.13 mg·g-1 at 30°C. The adsorption capacity of the
physic nut residue activated carbon was comparable to commercial activated carbon.

Abstract: The removal of trichloroethylene (TCE) from water using activated carbon fibers (ACF) and activated carbon (AC) was investigated. Adsorption, as an efficient process to remove TCE from water was chosen; in particular with ACF and AC as adsorbents. The results showed that physisorption play important roles for adsorption of TCE onto activated carbon fibers, while the less important chemisorption. Langmuir and Freundlich models were then employed to correlate the equilibria data. The Langmuir model best described the AC adsorption isotherm of TCE, with R2 0.9942. Freundlich model best fitted the ACF adsorption isotherm of TCE, with R2 0.9978.

Abstract: Pyrolysis is one form of energy recovery process which has the potential to generate oil, gas and char products. The char becomes an attractive by-product, with applications including production of activated carbons that is useful as a sorbent for wastewater treatment and air pollution control. In this work, activated carbon was prepared from Coffee (Coffea Arabica L.) bean waste collected from local coffee houses. Char from pyrolysis of coffee bean waste at 900 °C contained high fixed carbon and low volatile content that was favorable for subsequent activation process. The char was activated via chemical treatment with sodium hydroxide (NaOH) at five different NaOH : char ratios (1:1, 2:1, 3:1, 4:1 and 5:1) and heat treated at 400°C for 15 minutes using a fixed bed reactor under nitrogen atmosphere with a flow rate of 100 mL/min. Result shows that NaOH works effectively as dehydration reagent around 400°C. Under the experimental conditions investigated, impregnation ratio of 1.0 was found to be suitable for producing high-surface area activated carbon. The surface area and total pore volume of activated carbons, which were determined by application of the Brunauer–Emmett–Teller (BET) and t-plot methods, were achieved as high as 802 m2/g and 0.80 cm3/g, respectively. The chemically activated carbons were found to be mainly type I carbons and had high adsorption property (Methylene blue adsorption = 284 mg/g and Iodine number = 1070 mg/g).

Abstract: High surface area activated carbon was prepared from waste tobacco after extracting nicotine with microbial enzymatic and chemical activation. Surface properties of the prepared carbons were performed using nitrogen adsorption, and the adsorption behavior of the prepared carbons under different operation conditions on methyl orange was investigated by a batch adsorption experiment. The experimental results show that: using waste tobacco 5.0035g and white- rot fungi volume is 2.0ml, under the conditions of enzymatic time of 36h, activation temperature at 600°C and activation time of 2h, the concentration of ZnCl2 activation is 20%,The BET surface area of carbons prepared reach 1356.53m2/g, the average aperture is3.78nm, and the hole dimension is0.17 ml/g. The adsorption amount on methyl orange of 43mg/L reach 4979.31mg/g, and it show high adsorption capacity.

Abstract: The aim of this paper is to study the adsorption characteristics of nitric oxide (NO) and sulfur dioxide (SO2) on raw coal activated carbon over temperature ranged 298～343K using a static volumetric adsorption apparatus. The adsorption equilibrium data for NO and SO2 were ﬁtted to Freundlich, Dubinin-Radushkevich (D-R) and Sips adsorption isotherm model. Isosteric heat of adsorption was determined by the Clausius-Clapeyron equation. It was found that Sips adsorption isotherm model is more suitable for description of NO adsorption process at 298K, 313K and 328K and SO2 adsorption process at 313K, 328K and 343K, however, D-R adsorption isotherm model is more suitable for description of the NO adsorption process at 343K and SO2 adsorption process at 298K. The isosteric heat of adsorption values of SO2 increase slightly as the adsorbed amounts increasing from 0.8 to 1.6mg/g, but the isosteric heat of adsorption values of NO show a converse trend. Meanwhile, NO and SO2 adsorbed on coal activated carbon at the four temperatures may be a dominant of physical adsorption.

Abstract: Two activated carbons employing Scrap Tire as precursor were produced by using two different activating agents, HCl and H2SO4 (fixed impregnation ratio 1:1). Both of activated carbons were allowed by single-step to get difference carbonized at 500, 600 and 700°C in a muffle furnace for 1 h. Activated carbons differed with the physical structure, chemical and adsorption properties which were derived from Scanning Electron Microscope, and N2 adsorption/desorption isotherms. Batched sorption studies were performed to compare the iodine and methylene blue adsorption properties of two carbons. The carbon materials obtained from sulfuric acid activation of 500°C has BET surface area as high as 1066.70 m2/g, Methylene blue adsorption and Iodine number of 288.90 and 590.50 mg/g, respectively. The surface area and adsorption properties of carbon produced using sulfuric acid activation were higher than that produced using hydrochloric acid activation. The results suggest the feasibility of the process from the point of view of both porous texture and adsorption yield.